gdbstub: Introduce gdb_get_float32() to get 32-bit float registers

Since we now use a GByteArray, we can not use stfl_p() directly.
Introduce the gdb_get_float32() helper to load a float32 register.

Fixes: a010bdb ("extend GByteArray to read register helpers")
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200414163853.12164-2-philmd@redhat.com>
Message-Id: <20200414200631.12799-14-alex.bennee@linaro.org>

include/exec/gdbstub.h

@@ -125,6 +125,15 @@ static inline int gdb_get_reg128(GByteArray *buf, uint64_t val_hi,
     return 16;
 }
 
+static inline int gdb_get_float32(GByteArray *array, float32 val)
+{
+    uint8_t buf[sizeof(CPU_FloatU)];
+
+    stfl_p(buf, val);
+    g_byte_array_append(array, buf, sizeof(buf));
+
+    return sizeof(buf);
+}
 static inline int gdb_get_zeroes(GByteArray *array, size_t len)
 {
     guint oldlen = array->len;

target/sh4/gdbstub.c

@@ -58,11 +58,9 @@ int superh_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
         return gdb_get_regl(mem_buf, env->fpscr);
     case 25 ... 40:
         if (env->fpscr & FPSCR_FR) {
-            stfl_p(mem_buf, env->fregs[n - 9]);
-        } else {
-            stfl_p(mem_buf, env->fregs[n - 25]);
+            return gdb_get_float32(mem_buf, env->fregs[n - 9]);
         }
-        return 4;
+        return gdb_get_float32(mem_buf, env->fregs[n - 25]);
     case 41:
         return gdb_get_regl(mem_buf, env->ssr);
     case 42: